Prototype injection molds are expensive. They are typically machined out of steel or aluminum which is both costly and time consuming, due to the complex geometries of most molds. [Dr. Jozsef Gabor Kovacs] works in the Department of Polymer Engineering at Budapest University, which is where he came up with the innovative approach of using 3D printing to produce a prototype mold.

The mold was printed in Digital ABS PolyJet Photopolymer plastic using a Objet Connex 3D printer. The injection material used was polyacetal; which has a fairly low melting point of 175°C. By using this method they were able to go from a prototype mold to a test part in less than 24 hours. We don’t even want to think about how expensive that would be to expedite from a machine shop.

After the break you can watch the entire production process from printing to molding.

[Dan] has his own Stratasys Dimension SST 768 3D printer. It’s a professional grade machine which does an amazing job. But when it comes time to replace the cartridge he has to pay the piper to the tune of $260. He can buy ABS filament for about $50 per kilogram, so he set out to refill his own P400 cartridges.

Respooling the cartridge must be quite easy because he doesn’t describe the process at all. But the physical act of refilling it doesn’t mean you can keep using it. The cartridge and the printer both store usage information that prevents this type of DIY refill; there’s an EEPROM in the cartridge and a log file on the printer’s hard drive. [Dan] pulled the hard drive out and used a Live CD to make an image. He loaded the image in a virtual machine, made some changes to enable SSH and zap the log file at each boot, then loaded the image back onto the printer’s drive. A script that he wrote is able to backup and rewrite the EEPROM chip, which basically rolls back the ‘odometer’ on how much filament has been used.